Method and apparatus for customizing tool paths for aircraft parts

Abstract

A method and apparatus for customizing tool paths. A reference tool path is identified for a tool based on an expected shape for a surface of an object. Offset data is generated for a plurality of sample points identified for use in evaluating the surface of the object. The offset data identifies a difference between the expected shape for the surface of the object and an actual shape of the surface of the object. The reference tool path is modified using the offset data to form a modified tool path for the tool.

What is claimed is: 
     
       1. A method comprising:
 generating a three-dimensional model of a reference object, wherein the three-dimensional model includes a surface profile of the reference object; 
 identifying an expected shape for a surface of an object using the surface profile of the reference object, wherein the object and the reference object are objects of a same type manufactured according to the same manufacturing specifications, wherein both the reference object and the object are aircraft parts that have been used in a same manner but on two different aircraft; 
 identifying a reference tool path for performing a number of operations with a tool based on the expected shape for the surface of the object; 
 identifying a sampling path for evaluating the surface of the object based on the expected shape for the surface of the object, wherein the sampling path comprises a plurality of sample points that defines a grid pattern for evaluating the surface of the object based on the expected shape for the surface of the object, wherein a density of the sample points within a particular area of the grid pattern is determined by at least one of an amount of variation in the expected shape within the particular area, a complexity of the expected shape within the particular area, and an edge of the object corresponding to the particular area; 
 generating offset data for the plurality of sample points in the sampling path, wherein the offset data identifies a difference between the expected shape for the surface of the object and the actual shape of the surface of the object; 
 modifying the reference tool path using the offset data to form a modified tool path for the tool; and 
 performing the number of operations at the surface of the object using the tool and the modified tool path. 
 
     
     
       2. The method of  claim 1 , wherein the object is a workpiece. 
     
     
       3. The method of  claim 1 , wherein identifying the reference tool path for the tool based on the expected shape for the surface of the object comprises:
 identifying the reference tool path for the tool based on the expected shape for the surface of the object indicated by the three-dimensional model, wherein the reference tool path is comprised of a plurality of points in which each of the plurality of points corresponds to a position and an orientation for the tool. 
 
     
     
       4. The method of  claim 3 , wherein modifying the reference tool path using the offset data to form the modified tool path for the tool path comprises:
 modifying each of at least a portion of the plurality of points along the reference tool path using a corresponding subset of the offset data and a weighting algorithm to form a plurality of modified points that form the modified tool path. 
 
     
     
       5. The method of  claim 4 , wherein modifying at least a portion of the plurality of points along the reference tool path using the corresponding subset of the offset data and the weighting algorithm to form the plurality of modified points that form the modified tool path comprises:
 selecting, for a point in the plurality of points along the reference tool path, a portion of the plurality of sample points within a selected range of the point selected; and 
 identifying a portion of the offset data corresponding to the portion of the plurality of sample points selected as the corresponding subset of the offset data for the point. 
 
     
     
       6. The method of  claim 1 , wherein generating the three-dimensional model of the reference object comprises:
 generating the three-dimensional model of the reference object, wherein the reference object and the object belong to a group of objects designated for processing. 
 
     
     
       7. The method of  claim 1 , wherein performing the number of operations at the surface of the object using the tool and the modified tool path further comprises:
 performing the number of operations at the surface of the object using the tool and the modified tool path, wherein the number of operations comprises a scarfing operation performed according to the modified tool path. 
 
     
     
       8. The method of  claim 7 , wherein performing the scarfing operation further comprises:
 removing a portion of material up to a selected depth relative to the surface of the object. 
 
     
     
       9. The method of  claim 7 , wherein performing the scarfing operation further comprises:
 removing the portion of material with a mill device, a routing device, a sanding device, or a cutting device. 
 
     
     
       10. The method of  claim 1 , wherein generating the three-dimensional model of the reference object comprises:
 imaging the reference object with an imaging system, wherein the imaging system is selected from one of an ultrasound imaging system, an infrared imaging system, a computed tomography imaging system, and a laser imaging system. 
 
     
     
       11. A computer-implemented method comprising:
 generating a three-dimensional model of a reference object, wherein the three-dimensional model includes a surface profile of the reference object; 
 identifying an expected shape for a surface of an object using the surface profile of the reference object, wherein the object and the reference object are objects of a same type manufactured according to the same manufacturing specifications, wherein both the reference object and the object are aircraft parts that have been used in a same manner but on two different aircraft; 
 identifying a reference tool path for performing a number of operations with a tool based on the expected shape for the surface of the object; 
 identifying a sampling path comprising a plurality of sample points for use in evaluating the surfaces of the group of objects that defines a grid pattern for evaluating a surface of an object of the group of objects based on the expected shape for the surface of the object, wherein a density of the sample points within a particular area of the grid pattern is determined by at least one of an amount of variation in the expected shape within the particular area, a complexity of the expected shape within the particular area, and an edge of the object corresponding to the particular area; 
 receiving a plurality of measurements generated for the plurality of sample points in the sampling path from a surface measurement device; 
 generating offset data using the plurality of measurements, wherein the offset data identifies a difference between the expected shape for the surface of the object and the actual shape of the surface of the object; 
 modifying the reference tool path using the offset data to form a modified tool path for the tool; 
 directing a tool along the surface of the object using the modified tool path. 
 
     
     
       12. The computer-implemented method of  claim 11  further comprising:
 generating commands for use by at least one of the tool and a robotic system configured to operate the tool to move the tool along the modified tool path. 
 
     
     
       13. The computer-implemented method of  claim 11  further comprising:
 generating commands for use by at least one of the surface measurement device and a robotic system configured to operate the surface measurement device to move the surface measurement device along the sampling path and generate the plurality of measurements along the sampling path. 
 
     
     
       14. The computer-implemented method of  claim 11 , wherein modifying the reference tool path using the offset data to form the modified tool path for tool comprises:
 modifying each of at least a portion of a plurality of points along the reference tool path using a corresponding subset of the offset data and a weighting algorithm to form a plurality of modified points that form the modified tool path. 
 
     
     
       15. The computer-implemented method of  claim 11 , wherein performing the number of operations at the surface of the object using the tool and the modified tool path further comprises:
 performing the number of operations at the surface of the object using the tool and the modified tool path, wherein the number of operations comprises a scarfing operation performed according to the modified tool path. 
 
     
     
       16. The computer-implemented method of  claim 15 , wherein performing the scarfing operation further comprises:
 removing a portion of material up to a selected depth relative to the surface of the object. 
 
     
     
       17. The computer-implemented method of  claim 15 , wherein performing the scarfing operation further comprises:
 removing the portion of material with a mill device, a routing device, a sanding device, or a cutting device. 
 
     
     
       18. The computer-implemented method of  claim 13 , wherein generating the three-dimensional model of the reference object comprises:
 imaging the reference object with an imaging system, wherein the imaging system is selected from one of an ultrasound imaging system, an infrared imaging system, a computed tomography imaging system, and a laser imaging system.